Synthesis of lubricating oils



l atented Aug. 31, 1937 umrso STATES 2,091,398 SYNTHESIS or LUBRICATINGOILS Frederick W. Sullivan, Jr., and Vanderveer Voorhees, Hammond, Indassignors to Standard; Oil Con'lpany, Chicago, 111., a corporation ofIndiana No Drawing. Application March 21, 1931', Serial No. 524,412

7 Claims.

The present invention relates to the production of lubricating oils bysynthesis by means of catalysts from olefin hydrocarbons.

It has hitherto been proposed to subject various unsaturatedhydrocarbons such as amylene, butylene and ethylene to the action ofvarious catalysts of the type of aluminum chloride, thereby formingheavier oils of a viscosity suitable for use as lubricating oils. Theheavy oils thus pro- 10 duced, however, have been found to undergomarked changes in viscosity with changes in temperature, being inferiorin this respect to natural oils, such as the lubricating oils derivedfrom Pennsylvania oils, and in many cases inferior to the naturallubricating oils derived from Mid- Continent and naphthenic oils.

It has also hitherto been proposed (U. S. Patent 1,955,260) to subjecthydrocarbon waxes to pyrolytic decomposition whereby olefin hydrocarbonsare produced largely within the gasoline boiling range, and thereafterto subject the resulting mixture of unsaturated hydrocarbons to thepolymerizing action of aluminum chloride. In that process no attempt wasmade to isolate and polymerize hydrocarbons having a selected boilingrange.

We have now discovered that by subjecting olefin compounds, andparticularly straightchain olefin compounds individually to the actionof aluminum chloride and similar catalysts, said hydrocarbons having 8or more carbon atoms, the heavy oils secured as a result of thepolymerization are markedly superior to natural oils in theirtemperature-viscosity characteristics, the

changes of viscosity with increasing temperature being less than thosetaking place in typical oils, for example, of Pennsylvania origin and oflike viscosity.

The olefin hydrocarbons subjected to treatment in accordance with thisinvention have ranged from octene to cetene. The hydrocarbon selected issubjected to treatment with a suitable quantity of the catalyst, say 1to 5% and in general about 2%, for six to ten hours at temperatures offrom to 100 C. and the resulting product allowed to settle to separatethe aluminum chloride sludge from the polymerized oil. The sludge isseparated and the oil, preferably after Washing with alkali such assodium hydroxide 50 solution, and water, is reduced by fire. and steamdistillation to a bottom of the desired viscosity. Under the conditionsset forth, the polymerized oil derived from normal octene and reduced toa viscosity of 88 seconds Saybolt at 210 F. was

found to have a viscosity of 905 seconds Saybolt at F. This oil had acold test of 25 F. or -31.6 C.

The oils secured from individual olefins of higher carbon content aresimilar with respect to their temperature-viscosity characteristics, orbetter than that derived from octene. With increasing carbon content ofthe olefin treated, oils of higher cold test are secured. Thus, bytreatment with cetene, and reduction of the polymerized oil to aViscosity of 108 seconds Saybolt at 210 R, an oil is secured having aviscosity of 717 seconds Saybolt at 100 F. and a cold test of 35 F. orl.'7 C. The treatment of dodecylene in a similar manner likewiseproduces an oil of low sensitiveness to temperature changes.

Other known polymerizing agents having a similar action to aluminumchloride may likewise be employed, such as boron fluoride, zincchloride, ferric chloride, and the like.

We claim:

1. In the method of producing a synthetic lubricating oil wherein anolefin hydrocarbon is subjected to the polymerizing action of acatalytic quantity of aluminum chloride at a temperature below 100 0;,the aluminum chloride forms a sludge with a portion of the olefinmaterial which is separated from the polymerized oil and the separatedoil is freed from hydrochloric acid, the improvement which comprisesemploying as the initial olefin material normal olefin hydrocarbonshaving at least 8 carbon atoms and substantially free from lowermolecular weight olefins, whereby there is produced lubricating oils ofabnormally low viscosity temperature coefiicient.

2. The process of producing synthetic lubricating oils of low viscositytemperature coefiicient, which comprises subjecting a normal olefinhydrocarbon material, consisting principally of olefins having between 8and 16 carbon atoms to the action of from 1 to 5% of aluminum chlorideat a temperature not exceeding 100 C. whereby the olefin hydrocarbon is.polymerized to a viscous oil and the aluminum chloride is converted intoa sludge, separating said sludge from said oil, neutralizing said oiland subjecting it to distillation to obtain the desired product.

3. The process of producing a synthetic lubricating oil having aviscosity temperature coefficient less than that of a Pennsylvanialubricating oil of equivalent viscosity, comprising subjecting a normalolefin hydrocarbon. having between 8 and 16 carbon atoms to the actionof a catalytic quantity of aluminum chloride at a temperature notexceeding 100 C. whereby the olefin hydrocarbon is polymerized to aviscous oil and the aluminum chloride is converted into a sludge,separating said sludge from said oil, neutralizing said oil andsubjecting it to distillation to obtain the desired product.

4. The process of claim 3 wherein the normal olefin hydrocarbon employedis normal octene.

5, The process of claim 3 wherein the normal olefin hydrocarbon employedis normal duodecylene.

6'. The process of claim 3 wherein the normal olefin hydrocarbonemployed is cetene.

7. In the method of producing a synthetic lubricating oil whereinanolefin hydrocarbon is subjected to the polymerizing action of a catalystselected from the class consisting of aluminum

